There are presently in use containing vessels used in different industries such as chemical, food processing, metallurgical and the like. In vessels of this nature chemical reactions are conducted, polymerization procedures are carried out, beer is brewed, metals or other materials are mixed, and other procedures are carried out under controlled temperature and pressure conditions. It is necessary in each of these procedures to control and determine the progress and alter or adjust the reaction conditions when necessary. This control is generally facilitated by a viewing window provided in the side of the reaction vessel. By viewing through this window, the operator can determine color changes, liquid levels, or other visually-determinable factors taking place within the vessel. These viewing windows can fail after continued or prolonged usage and could cause serious injury to the operator. Window failure can be caused by several factors such as corrosion, gasket failure, glass fractures, high pressures or uneven glass loading due to attachment stresses and the like.
There have been some attempts to improve the durability of viewing windows and some improvements have been disclosed in U.S. Pat. Nos. 2,744,487; 3,299,851; 3,837,226 and 4,245,566. Each of these patents disclosed a different approach but all lacked the feature of providing a corrosion-reducing system or a structure that substantially strengthens the window after continued usage. None of these patents provided viewing windows sufficient to prevent rupturing of the window when used in high pressure vessels that are exposed to corrosive conditions.
U.S. Pat. No. 4,809,862 (Canty) provided a safety viewing window made up of an optically clear window having a transparent disc fused to a metal frame. A laminate was then overcoated over the fused disc and frame to provide a corrosion-resistant viewing window. The viewing window has means for securing it to the vessel in a pressure-tight manner. The unit has found wide acceptance but a unit was needed to record activities within the vessel or to provide observation means at a remote location. There are situations requiring controlling and recording process parameters as they occur for viewing immediately or at a later date. There are other situations when the operator is absent from the vessel site and process progress needs to be viewed or recorded. In other situations, vessel reactions could cause explosions or other dangerous reactions. To accommodate these situations, the present invention provides a camera-viewing structure allowing viewing or recording at a remote location where information can be digitized if desired to be analyzed or viewed at a later date. Window viewing by an observer can only provide instant viewing. If it was desired to play back a chemical reaction to determine color changes, liquid levels or other parameters, instant viewing through any type window would not provide this opportunity. A camera viewing device would afford substantial advantages in addition to safety.
In standard viewing in a high pressure/high temperature system, users have been limited to makeshift methods. Generally, to view the interior of a vessel at a remote location, the user would have to mount a CCD or CCTv Camera onto an existing sightglass window. They would then encounter some or all of the following problems that would render the system ineffective:
(1) The sightglass and CCD lens would become dirty due to dirt external to the vessel.
(2) The process fluid or vapors would leak out or flow out due to a sightglass breaking or leaking. This would then destroy the electronics making the system worthless.
(3) Reflection from room lighting would cause the vessel view to disappear.
The structures of a camera device on a reaction vessel could easily become corroded and could fail. Uneven glass loading due to uneven bolt or gasket stresses can cause cracking and leakage. Also, corrosive chemicals during extended usage could cause failure of these mounting structures or failure of the camera being used. The camera systems of the prior art are cumbersome, oversized and in many instances tend to reflect light and cause image distortion. In addition, focusing and manipulating of the camera to provide optimum usage has been difficult when using prior art devices. Therefore, while some degree of improvement is provided by camera viewing heretofore used, none of these systems provide an adequate system for reliable and extended usage.